Directly-driven slewing gear for drag-line excavators



Sept. 8, 1925.

' H. O. BEDGOOD DIRECTLY DRIVEN SLEWING GEAR FOR DRAG LINE EXCAVATORS Filed July 10, 1924 Patented Sept. 8, 1925.

HnBERm- OSWALDIBEDGOGD, F vsco'rfmimlr .nssremm r0; nonwm'rz' e GOM- 'PANLY DIM-1mm for nnnrnmw; seem/Am).

DIREGZLLY-DRHTEN: ;SL-EW EIG GEAR EOB'iDRAGeIJNE' :EXGAYAT-ORS..

Anplieationhisdil'ulflO,1924; sfilialcnfl. 725,252..

' Di'unbreck', Gl'ssgow, Scatland; a subjected the King-0f 'Grreat Britain, ,haveflinvented centain new and usefiilIinQrovedDi'rectIy- Driven: file-Wing. Gears for Drag-Line Excavators, of'whi h} the fcllvving is a; specificstion.

This invention relates, to. drag; line eX- cavatorsandrhasfor its bject' to provide improved slewing gear aEor: such machin s- Drag. line Y excavators, as 1st. pres-mtcenssti'xueted,- siren-smelly pncvi'ddjwithislewing s ;e2i r v comprlsnrg .a hxed circular Snack andlia pi ion; Wheel, v.WIii JEL letter zi$ .d1 iVell ithrei gh gearing by an engine t .011. the, turntable.

Ahcordiilg t'oithis invention the slewing ef; the eXfiiWaton jib. :is. efleetedi' by s dinet 20 without using,jiitermediete gearjn g oflsny kind," whereby the, construct'ibngandllactlnn drive from the slewin'g enginete, rnien of the slewing gear is veonsfrderehly simplifiedi v It iselse en .oblject of-f the p resent li nvention to providesini plifiedrneehan fsm. s9, ,thet th slewing,- spammed-can be cqn folfiledlby the manipulation :of I awsihgle hh'nddever; c.

Qne elnbbd ment .voifhth'e' inventicn i wi'll fnow; be descr bed by ay, toilexemple and with; neteienee. t0 fliie' aecompanymgfdravvings. v v

Ohthedrawings1- t g, l ,i, as vside Vi'GzWr efflthe :slevving gear parrtlyinseetien along tlielineilf 1- fEii-g'. 2. The .rev rsing gear, endgsheftj hearings came in; section While. the, turntable: 45f offthe machine is in outline. t

, Eig.: 2 is: a -1an.-. View. offthe igeair and'eni tii F1 3 dSylIl en1argeddeta11 vlew of'th'ere versing gear;

The-d ng line A, its fairlead 'Bgaind pert 5* "j O 3116 i di' ted ,ft0. show they rele- Jtivepo's iticns of the .p a ti t x t V e m sgnowto the-accoifngps yingidraiii rf1gs;, the; numeral. 1 denotes: the stationary under-frame ofthe drag, line excavator V here/ 111smountedathe circular, reek .Zwi'th vertical teeth 3"Qnit's' i ner walk! Gbncene gine is effected by; er system' of'rods' and,

trig. with. andnbove the said-rack there is pivoted'the 'nsjual revolving, fr aine of mm tab e 4%.Wh'iph0arries the jib CL. 7 is the slewing pinmnvvhichgears ,Withthe rack,

The engine has; two cylinders 5, 5;; arranged, at an anglensay, .90 The single vertical 'drivingfshzift' 6 has the slewing pin nm 7 atitslewer end and passes through the revolving, frame or turntable 4 at! the point asfldeserihed 'onl yfene. ecaentric. sheave 1353s V requlredtcqpemte the, valve gears-of the cylinders thje ecc'ent'ricjstrep- 14 .of the: said eccentrlc being; cdnnected f tic-"two eccentric r.o ds&1'5,' one to. Search ofkthetcyliinders 5. 51:

Reversalicf fliefengineis' f pr0vided :for; by

turning the aforesaid eccentric, sheave 1'3 round the driving "shazftl 6 "by sliding sleeve and r0l1 gear shown clearly i'nwFigs 31' 'Do this e'nd,,a hel'ifx 16' is cut 'fcrai'ciertain length in the upper end ofthemsh'aft '61 A sleeve 17 surrounds t11isporti0nI of the, shaft 6Qand engsgeswith thefheli'x therein formed; The eccentric slzi'ezwe 13 has aneextendedfsleeve 18 frmedion its. lower side; the said sleeve embracing. the, aferement'ioned" sleeve. 17.

Registering,keyways are cut" in th etvvo -.s1ee ves.11',7" and-[18. and key.v 19isinserted'1in such .a Way, thatzthe said sleeves can slide,

b'nteannot rotate-relatively .to each other. Thefbushing of. the, upper guide rod 9- herei'nbefie're clescribediis extended into a 011920 in which the-sleevel8 Works. Thesleeve 17 has denblefiang'es formed atv its upper end to receive the prQngs-o f a fork 21, which fdrl iis cennectldlto the reversing lever 22,

fiilcr umed at 22 and operated by "a reversinga'enjgine 23; This lever- 22 also zcontrols the f S t6fl1-I l S1ide-Va1V6 24,1 threughl which steam is suppliedto pipes 25, 25 and" thence t the cylinders. The valve 2 L'is5closedin the eentraljp'esition' and" open in, the other two positionsf The pi-pe s "2' 8 are theqcylinder exhsuStS-J COntrOI of thjei reversingf enlevers 26 operated by a lever 27 from any convenient part of the revolving platform or turntable l.

Supposing the parts to be at rest in the central position, the operation of the reversing and slewing gear is as follows 2- Steam is admitted to the engine 23 and the fork 21 caused either to rise or fall according to the direction in which the jib of the excavator has to be moved. Fork 21 causes axial displacement of the sleeve 17 which, in virtue of its engagement with the helix 16, rotates. In turning, the said sleeve 17 also rotates the surrounding sleeve 18 of the eccentric, no axial motion of which occurs. Thus the eccentric sheave 13 is rotated to the position which moves the slide valves of the cylinders 5 to effect the rotation of the pinion 7 and consequently the slewing motion in the direction required.

The helix 16, in this embodiment of the invention, is a left hand screw; therefore, while the shaft 6 is rotating, say, in a clockwise direction as seen in plan, the sliding sleeve 17 will tend to work down the shaft. Consequently, a counter-balancing thrust will be required to be exerted by the engine 23 at the other end of the fork 21. The thrust will be downward and will require to be maintained as long as the engine is running in that particular direction.

To reverse, either this counter-balancing thrust is diminished or a thrust exerted in the opposite direction, when reversal will take place as hereinbefore described, a very small movement of the sleeve being sufficient therefor. Motion of the reversing lever 22 will produce a movement of the valve 2 1, which controls the steam supply.

To stop, the sleeve 17 is allowed, or caused, to move to the central position, the resulting movement of the lever 22 operat ing the valve 24 and moving it to its central position thereby shutting off steam.

The reversing engine used is preferably of the known combined steam and hydraulic type frequently fitted for the reversal of heavy marine reciprocating engines, and comprises a steam cylinder below, a controlling oil cylinder above, and a piston rod common to both and having a piston in each cylinder. A valve admitting steam to the steam cylinder and a valve controlling the flow of oil in the oil cylinder are interconnected and are provided with a. hunting gear to bring them back automatically to their closed positions after operation of the engine, the piston rod being held in any desired position.

In the present instance the piston rod is connected to the reversing lever 23 so that the slidingsleeve 17 and sheave 13 can be maintained in any required position. The reversing engine, and consequently the whole slewing gear, is operable by a single lever 27 through rods and levers 26.

It will be apparent from the foregoing description that, according to this invention, a very simplified slewing gear is provided for drag line excavators, wherein all intermediate gearing is dispensed with and the engine design improved in such a way that the whole slewing operation is controlled by the movements of one lever.

Having now fully described my invention what I claim and desire to secure by Letters Patent is:

1. A drag line excavator having, in combination, an underframe, a circular rack upon said underframe, a turntable mounted for rotation on said underframe, a. vertical shaft carried by the turntable and carrying on its lower end a pinion that gears with the rack, a slewing engine which drives the said shaft directly, and a scroll gear on the said shaft which causes theengine to stop, go ahead or reverse.

2. A drag line excavator having, in combination, an. underframe, a circular rack upon said underframe, a turntable mounted for rotation on said underframe, a vertical shaft carried by the turntable and carrying on its lower end a pinion that gears with the rack and a slowing engine having two cylinders arranged at an angle to one another and which conjointly drive the said shaft directly.

3. A drag line excavator having, in combination, an underframe, a circular rack upon said underframe, a turntable mounted for rotation on said underframe, a vertical crankshaft carried by the turntable and carrying on its lower end a pinion that gears with the rack, a slewing engine having angularly disposed horizontal cylinders driving a single crank on the vertical crankshaft, and reversing gear comprising an eccentric rod for each cylinder, a single eccentric sheave to which the eccentric rods are connected, a scroll gear connecting said sheave to said crankshaft whereby the position of said sheave relatively to the crank may be changed to cause the engine to stop, go ahead, or reverse, and means to alter the position of the scroll gear.

4. A drag line excavator having, in combination, an underframe, a circular rack upon said underframe, a turntable mounted for rotation on said underframe, a vertical crankshaft carried by the turntable and carrying on its lower end a pinion that gears with the rack, a slewing engine having angularly disposed horizontal cylinders driving a single crank on the vertical crankshaft, a valve controlling the steam supply to the cylinders and adapted to close in central position, and reversing gear comprising an eccentric rod for each cylinder, a

single eccentric sheave to which the eccentric rods are connected, a scroll gear connecting sai-d sheave to said crankshaft whereby the position of said sheave relatively to the crank may be changed to cause the engine to stop, go ahead, or reverse, a lever connected to the scroll gear to alter its position, and a connection from the said lever to the steam valve whereby the valve and the scroll gear are altered simultaneously.

5. A drag line excavator having, in combination, an underframe, a circular rack upon said underframe, a turntable mounted for rotation on said underframe, a vertical crankshaft carried by the turntable and carrying on its lower end a pinion that gears with said rack, a slewing engine having two horizontal cylinders disposed at 90 to one another and both driving a single crank on the vertical crankshaft, a single valve controlling the steam supply to both cylinders, and reversing gear comprising an eccentric rod for each cylinder, a single eccentric sheave to which both eccentric rods are connected, means whereby the position of the sheave relatively to the crank may be changed to cause the engine to go ahead or reverse, a lever to operate the said means, and a connection between the said lever and the'steam valve whereby the said valve and the said reversing gear are operated simultaneously by the one lever.

In testimony whereof I aflix my signature.

HUBERT OSWALD BEDGOOD. 

